Air brake apparatus



Sept. 28 i926.

S. G. NEAL AIR BRAKE APPARATUS Filed Feb. 1'7

1925 3 sheets-sheet 2 NSM@ lNVENTOR Spencer 6. /l/ea.

ATTORNEYS Sept. 28, 1926.

S. G. NEAL AAIR BRAKFl APPARATUS Patented Sept. 28, 1926.

UNITED SPENCER Gr. NEAL, OF NEW YORK, N. Y., ASSIGNOR TO AUTOMATIC STRAIGHT AIR- BRAKE COMPANY, OF ViILlVIING-TON, DELAW'ARE, A CORPORATION OF DELAWARE.

AIR-BRAKE APPARATUS.

Application filed February This invention relates to improvements in triple valves of the Westinghouse type. In triple valves of this type the main piston, the main slide valve and the graduating valve are moved to release and charging position by an increase in brake pipe pressure. Upon a reduction of brake pipe pressure for an application of the brakes the auxiliary reservoir pressure moves the main piston and the connected main and graduating valves into application position and air flows from the auxiliary reservoir to the brake cylinder. When the auxiliary reservoir pressure has been suiticiently reduced through the flow of air to the brake cylinder the brake pipe pressure will move the main piston and the graduating valve to lap position.

One of the important objects of this invention is to provide a triple valve of the standard Westinghouse type with means Jfor securing a graduated release of the brake cylinder pressure.

Another important object of the invention is to provide a standard l/Vestinghouse type of triple valve with an independent suppleinentary or pilot valve means operated to service position by a. reduction in brake pipe pressure, and which in service application position will connect the brake pipe to the brake cylinder, the main valve means comprising the main and graduating valves, controlling communication between the auxiliary reservoir and the brake cylinder.

Another object or the invention is to provide a supplementary or pilot valve which will be controlled in its movements by brake pipe pressure, emergency reservoir pressure and brake cylinder pressure.

Another important object of the invention is to provide means whereby the supplenentary or pilot valve will act as a brake cylinder pressure controlling means and ensure a brake cylinder pressure substantially in direct proportion to the brake pipe reduc-tion regardless of brake cylinder pistou travel and brake cylinder leakage.

Another object of the invention is to provide a triple valve, of the type herein described, with a release governing valve having two positions, in one of which the main slide valve in release position will bring about a normal full and quick release of thc brakes, the release governing valve in its other position rendering the main slide 17, 1925. Serial N0. 9,789.

valve ineffective in release position, the release of brake cylinder pressure then being controlled entirely by the supplementary or pilot valve.

. Another important obj ect of the invention isT to provide means whereby a standard Vv estinghousetype of freight triple valve in cycling operations will automatically build up the brake cylinder pressure above that which would be normally obtained from a given brake pipe reduction, the said build-up of brake cylinder pressure being wholly dependent. upon the rapidity of the cycling operations so that onlow grades thelbrake cylinder pressure will not be built up as high as on heavy grades where the cycling operations are frequent and of short duration. The purpose of this automatic buildup oin brake cylinder pressure is to avoid the use of manually settable retainers in grade braking.

There are many other important objects and advantages of the invention which will hereinafter appear.

I n order to simplify the description the yarious ports and passages will be described in connection with the various operations oi' the triple valve.

In the drawings, Fig. l is a diagrammatic sectional view orn the triple valve embodyingr the invention, the parts being shown in full release and charging position, the release vgoverning valve being in quick release position;

Fig. 2 a view similar to Fig. l showing Full release and charging position.

The system is charged by increasii'ig the brake pipe pressure, as in the present standard lVestinghouse type of air brake apparatus.v The air pressure from the brake pipe flows through the brake pipe connection 2, the connected passage 3 into the main piston chamber' 1. The increasing pressure in chamber 1 forces the main piston 44 inwardly, toward the right hand as viewed in the drawings. Connected to the piston is the usual valve stem 45, said stem extending inwardly through the main slide valve chamber and being connected to the main slide valve 6 and the graduating valve 56 in the usual manner. The piston stem is connected to the main slide valve by a lost motion connection and the graduating valve is connected directly to the said stem as is usual in this type oi apparatus. The main slide valve operates on a main slide valve sea-t through which various ports and passages are formed. lilith the main piston in full release and charging position a charging groove 4 is uncovered so that air may flow from chamber 1 through said groove past the piston 44 and into the main slide valve chamber 5. The main slide valve chamber is connected directly to the auxiliary reservoir through passage 7. Said chamber 5 is also connected to an emergency reservoir through passage 8, chamber 9 and a. port controlled by a spring-pressed check valve 10. The spring 10 normally holds the check valve seated and the rising pressure in chamber 9 will unseat said valve and open communication between chamber 9 and the emergency reservoir. The auxiliary reservoir and the emergency reservoir will therefore be charged at the same time and at the same rate. From chamber 1 brake plpe air will flow through the passage 11 into brake p-ipe chamber 12 of the diaphragm structure. The lower wall of chamber 12 is formed by a brake pipe dia- 3hragm 13. low the diaphragm 13 is a larger brake cylinder diaphragm 53, said diaphragm being considerably larger in area than the brake pipe diaphragm 13. The diaphragms 13 and 53 form the upperrand lower walls of a brake cylinder chamber 53. Below the brake cylinder diaphragm 55 is arranged an emergency reservoir diaphragm 16, this diaphragm being of the same area as the brake pipe diaphragm 13. Between the diaphragms 53 and 16 is formed a retention chamber 26; and below the emergency reservoir dia.- phi'agm 16 is formed an emergency reservoir chamber 17. This latter chamber is connected to the emergency reservoir by passage 18 so that said chamber will be charged with emergency reservoir air.

The diaphragms 13, 53 and 16 are rigidly connected together at their centers by a stem 13a and move up and down together. These diaphragms have a limited up and down movement, suitable stops being previded for that purpose. In the brake cylinder equalizing chamber 55 is arranged a horizontal lever i which is pivotally con- Spaced a suitable distance be-V nected to the stem 13a. One end of said lever is pivotally connected to the valve casing, its otherI end being connected to a seccndary or pilot valve 15, said valve being arranged in a valve chamber 14. The chamber 14 is directly connected to the brake pipe chamber 12 by a; passage 14El so that brake pipe chamber pressure will always be registered in the chamber 14 and the pressures in the chambers 12 and 14 will always be equal.

With the triple valve parts in full release and charging position, with the release governing valve in-quick .release position, as shown in Fig. 1, the brake cylinder is in direct communication with atmosphere through brake cylinder passage 19, cavity 20 ot' the main slide valve, passage 21 which leads direct to the release governing valve chamber 22, and from this chamber to atmosphere through port 23 in the release governing valve 57, and main atmospheric port 24.

The check valve 10 is opened for emergency applications of the brakes by means oi a piston 30 and a lever 30a connected thereto and adapted to bear on the projecting end of the valve 10. The piston 30 reciprocates in a chamber 30In and said chamber is charged from the main slide valve chamber through port 31 and cavity 31a in the main slide valve and port and passage 32 which leads from the main slide valve seat into chamber 30". The piston 3() therefore 4is subject on one side to the pres- -sure in chamber 9' and on its other side to the pressure in chamber' 30b and said piston remains inoperative in all positions ot the main slide valve except the emergency position, as will be hereinafter described.

A chamber is `connected by passage 25a to the retention chamber 26 and is for the purpose of augmenting said chamber 26. The chamber 25 has no function except in graduated release operations, as will be hereinafter described. With the release governing valve in quick release position, as shown in Fig. 1, chamber 25 is vented directly to atmosphere through passage 27. cavity 28 of the release governing Vfalve, and port and passage 29 which leads direct to atmosphere. Chamber 25 is also connected to atmosphere through a small blow down port 25b which leads to the main slide 'valve seat and into a cavity 25c in the main slide valve. The cavity 25C connects the port 25b to an atmospheric port 25d. The chamber 25 is connected by a port 27a to the main slide valve seat and in the release position of the main slide valve this port registers with the cavity 2O in the main slide valve so that the chamber 25 is directly connected to the brake cylinder port and passage `19.

In emergency application the brake pipe is vented to atmosphere by opening the emergency brake pipe vent valve 34. This luc llo

.Fill

valve is connected to a piston 33 whichA reciprocates in a chamber eS6-361. The chamber 36 below the piston 33 is connected directly to the brake pipe by passage 35. lThe piston 33 is provided with a small lealfport 37 through which air will pass from chamber 36 into the chamber 36 above said piston. Brake pipe pressure will thereby equalize on opposite sides of the piston 33 and the valvel 34 will be held closed. A passage 3S leads from the chamber 3Gn above the piston 33 to the main slide valve seat. ln the emergency position of the main slide valve passage 33 is connected by a cavity in the main slide valve to a port and passage which leads directly into a chamber 39 thereby reducing the pressure in chamber 36a and permitting the brake pipe pressure in chamber 36 to raise the piston 33 and open the valve 34. ln the release and service positions of the main slide valve chamber 39 is connected direct to atmosphere through cavity 4l, and secondary at mospheric port 42, as will be more fully hereinafter described. ln the service position of the main slide valve this communication is through port 43 and cavity 4l.

Service posz'z'oa.

A service application ot the brakes is brought about by a service reduction in brake pipe pressure in the usual manner and the pressure in chamber 1 will be reduced below the auxiliary pressure in chamber 5. Then a given differential in pressure has been established in thesey two chambers piston 44 and the stein 45 which is connected thereto, and the main Vand graduating valves Vwill be moved toward the left by the superior auxiliary reservoir pressure in chamber 5. The initial movement of the piston and the stein 45 will i'irst take up the lost motion between the extension 46 of the stem and the main slide valve. rlhis initial movement will also move the graduating valve to uncover the service port 49 in the main slide valve, Thereafter the main slide valve will move with the piston stem until the piston engages the graduating stem 47 where it will be stopped in service posi tion. The movement o' the stem 47 is resisted by the graduating spring 4S, said spring having suiiicient tension to hold the piston and the main slide valve in service position when a service reduction in brake pipe pressure has been made (see Fig. 2). The movement 01" the mainslide valve to service position closes communication between the brake cylinder passage'lQ and the release cavity 2O ot the slide valve 6 and the service Vport 49 is brought into register with the brake cylinder passage i9. Auxiliary reservoir air is then free to tlow from chainber 5 `direct to the brake cyl'nder through the passage 50 in the stem 45, port 49 ot the main slide valve and the brake cylinder passage i9 which leads direct to the brake cylinder. The size of the service port 49 is such as to permit a reduction oit the auxiliary pressure at practically the same rate as a service reduction ot brake pipe pressure.

vrihe purpose of this uniform reduction of both the brake pipe pressure and the auxil- `ary reservoir pressure is to prevent a pressure differential on piston 44 that would tend to compress the gracuating spring 4S, thus preventing the piston and the slide valves operating to emergency position when a brake pipe reduction is made only at a service rate. in this service position of the main slide valve chamber 30h will be in direct communication with the auxiliary reservoir chamber through passage 32, cavity 3la and port 3l ot the main slide valve and passage 5() in the main slide valve stem, with the result that there will be no movement ol' the piston 30 and the emergency reservoir will remain scaled. The brake cylinder will be connected to the equalizing chamber ol the pilot valve structure through passage 51, cavity G4 of the main slide valve and passage which leads direct to chamber This communication permits the supplementary or pilot valve to both supply and release air from the brake cylinder so long as the main slide valve 6 is in service position.

rlhe reduction or" brake pipe pressure in chamber l will result in a corresponding reduction oit pressure in the brake pipe chamber l2 ot the diaphragm structure, resulting in an upward movement ot the valve l5. This upward movement results from the reduction of the pressure in chamber l2 below the undisturbed emergency reservoir pressure in chamber 17 beneath the' diaphragm i6. lVhen the pilot valve l5 has been moved upwardly into service position brake pipe air will flow to the brake cylinder through port 54 in the pilot valve, equalizing chamber 55, passage 52, cavity 64 of the main slide valve and passage 5l which leads direct into the brake cylinder passage 19. It is therefore clear that in the service position or' the main slide valve air will ilow to the brake cylinder from auxiliary reservoir through the main slide valve and also from the b 1alie pipe to the brake cylinder through the independent pilot valve. Brake pipe air will be ut-ilized for building up the brake cylinder pressure and a quick serial action will result.

Service Zap position'.

The means which establishes the dual communication'between the auxiliary reservoir and the bra-ke cylinder and the brake pipe and the brake cylinder, are lapped independently of each other. The main valve means controlling' communication between the auxiliary reservoir and the brake cylinder is lapped on the volumetric principle whereby the main slide valve and piston will be operated to the right to cause the graduating valve to eut oli` communication between chamber 5 and port 49 ot the slide valve when the pressure in chamber 5 has been reduced slightly below the brake pipe pressure in chamber 1. This operation, in the standard Wrestinghouse type of Jfreight triple valve, takes place when a given volume has been exhausted trom the auxiliary reservoir, and the ei'lectiveness in resultant brake cylinder pressure is determined by the length of the brake cylinder' piston travel, which ot course, governs the brake cylinder volume. The connection between the brake pipe and the brake cylinder controlled by the secondary valve means is closed when a given brake cylinder pressure has been developed, this pressure beingl registered at all times in the equalizinschamber 55 and when this pressure is raisel to a point where the reduced brake pipe pressure in chamber 12 and the increase in pressure in the equalizing chamber 55 will oppose the undisturbed emergency reservoir pressure in chamber 17, the pilot valve will. be moved downward to lap position and the service port ot the pilot valve will he closed. Should the piston travel be short or less than normal (8) an abnormal brake cylin der pressure will be developed before the graduating valve 56 will be lapped, and th pressure in the equalizing chamber 55 between diaphragms 13 and 53 will likewise be abnormal. The diaphragms will be lowered and the pilot valve will be moved to release posit-ion and communication will be established between the brake cylinder and atmosphere so that the abnormal, developed, brake cylinder pressure will be reduced to normal pressure bythe balancing operation of the diaphragms. Should the piston travel be greater than normal the liow ol' auxiliary reservoir pressure to the brake cylinder will not develop a normal pressure therein, with the result that the pilot valve will be raised to or held in service position by the diaphragms and brake pipe pressure will then flow to the brake cylinder to make up any pressure which was lackingl at the time the graduating valve assumed lap position. The operation of the pilot valve as just described, will of course tend to reduce the brake pipe pressure which in turn will if sui'licient, again operate the graduating valve and piston to service position, so that the additional air required to develop normal brake cylinder pressure where there is an abnormally long piston travel will be taken from bot-h the auxiliary reservoir and the bfake pipe.y It the brake pipe pressure is held constantly at any predeterminned service reduction, the brake cylinder will be maintained against leakage by the diaphragm operated pilot valve 15 alone; but should another service brake pipe reduction be made, air pressure will flow to the brake cylinder both from the auxiliary reservoir and the brake pipe.

Quick release.

The release governing valve 57 is arranged to be manually operated by means ot the stem 57". This valve has two posi tions, a quick release position and a graduated release position. ln its quick release positon the large release port 23 connects the release governing valve chamber 22 to the large atmospheric port 24. This position ot the valve is illustrated in Fig. 1.

A release of brake cylinder pressure `is obtained by increasing the brake pipe pressure in the usual manner. lVhen the brake pipe pressure is raised in chamber 1 to exceed the pressure in the auxiliary reservoir chamber sufliciently to operate the piston and the main slide valve to release position communication will be established from the brake cylinder direct to atmosphere through the release cavity 2O of the main slide valve and thence to atmosphere through the release governing valve chamber 22 as de scribed in connection with the charging of the system. The auxiliary reservoir will be recharged `from the brake pipe through the charging groove el as hereinbefore described. It will not be necessary, however, to charge the emergency reservoir because the airin said reservoir has been maintained undisturbed. The movement of the main slide valve to release posit-ion carries the cavity (il out of register with the ports 51 and 52 ther lby preventing the pilot valve from feeding brake pipe pressure to the brake cylinder when the brake pipe pressure is raised at a slow rate for release of the brakes. The increased brake pipe pressure in chamber 1 will be directly registered in the brake pipe chamber 12 of the diaphragm structure and the diaphragms will be moved downwardly and will carry the pilot valve to release position. In the release position of this valve the equalizing chamber 55 will be connected to atmosphere through cavity 61 in the pilot valve, passage 62, cavity 41 ot the main slide valve and atmospheric port l2. The pressure in chamber 55 will not be completely exhausted to atmosphere until the brake pipe pressure in chamber 12 has been raised to an equality with the undisturbed reservoir pressure in chamber 17. The equalizing chamber' 55 will be cut off from communication with the brake cylinder when cavity 641- has been moved out of register with passage 52. It the communi`- cation between passages 51 and 51 were not cut ott and main slide valve did move to release position the operation would be as follows: The slow `increase in brake pipe pressure such as does exist 1n a long train when releasing the brakes, would operate the pilot valve to release position, and the' brake cylinder pressure would be released through the diaphragm structure, at a rate proportional to the increase in brake pipe pressure. But when the main slide valve is operated to release position to quickly `er1-- haust the brake cylinder pressure, the pressure in the equalizing chamber is also reduced at the same rate and the result would be that because of the quick reduction of pressure in chamber 55 the pilot valve would operate to service position and feed brake pipe air into the brake cylinder in the same manner as it would when maintaining brake cylinder leakage. With the communication closed between passages 51 and 52, the pilot valve operation is pre-- cisely as just described, but the brake pipe pressure entering passage 52 cannot flow to the brake cylinder through passage 51 because the Cavity 64 has been moved out of register with pasage 52.

Serrz'ee application when operating n graduated release.

The release governing valve is shifted to the left, as illustrated in Fig. 4 of the drawings, in order to adjust the triple valve for graduated release operations. This movement yof the release governing valve closes the large atmospheric port 24 and closes the atmospheric port 29. This movement of the valve therefore closes communication between the retention chamber 25 and atmospheric port 29 and also communication between the brake cylinder exhaust port 21 and the atmospheric port 24. A cavity 6U in the release governing valve will connect together passages 58 and 59. Passage 58 leads direct to the brake cylinder passage 19. Passage 59 leads direct to passage 52. Passage 52 leads from the main slide valve seat direct to the brake cylinder pressure equalizing chamber 55. When, therefore, the release governing valve is in graduated release position the equalizing chamber 55 is connected in all positions of the main slide valve, and independently of the main slide valve, with the brake cylinder Vpassage 19. The service operation of the triple valve as a whole is precisely as described under the heading Service position, the main slide valve in service posit-ion connecting the auriiliary reservoir to the brake cylinder and the independent or supplementary valve 15 connecting the brake pipe to the brake cylinder. Viith the release governing valve in graduated release position the equalizing chamber 55 is connected to the brake cylinder through passage 52, passage 59, cavity in the release governing valve, passage v58 to the brake cylinder passage 19 so thatl brake pipe air will flow to the brake cylinder independently of the main-slide valve.

Graduated release.

The release operation, when operating in graduated release is wholly controlled by the independent pilot valve 15, the release movements of the main slide valve being idle in graduated release operations.

lVhen operating in graduated release, an increase in brake pipe pressure will operate the piston and main slide valve'to re`ease position as hereinbefore described, but the brake cylinder pressure cannot be quickly released to atmosphere because the port 23 of the release governing valve is moved out of register with the atmospheric port 24. The purpose of connecting the passages 5S and 59 by the cavity 60 of the release governing valve is to permit the pilot valve to release brake cylinder pressure to atmosphere while the main slide valve is in release position, this being prevented when operating in quick release, as herein described. The flow of air from the brake cylinder to atmosphere will be, when operating in graduated release, as follows: Brake cylinder pressure will flow through passages 19 and 58, cavity 60 of the release governing valve and passages 59 and 52, which lead direct to the equalizing chamber 55 between diaphragms 18 and 53, and from this chamber to the atmosphere through cavity 61 to the pilot valve passage 62, cavity 41 of the main slide valve, and the atmospheric port 42.

From the above description it will be understood that when operating in graduated release the brake cylinder is supplied with pressure both from the auxiliary reservoir and the brake pipe when a brake pipe reduction is made; but the discharge of pressure therefrom is controlled entirely by the pilot valve and the amount of pressure reduction is dependent upon the amount of increase in brake pipe pressure.

The release of brake cylinder pressure will be in direct proportion to the increase in brake pipe pressure registered in the brake pipe chamber 12. By increasing the prossure in chamber 12 a predetermined amount, for instance live pounds, the diaphragm structure will be moved downwardly and the pilot valve will be moved to release position. Brake cylinder pressure in chainber 55 will be released to atmosphere as hereinbefore described. lVhen the pressure in chamber 55, and consequently in the brake cylinder, is reduced to such a degree that the undisturbed emergency reservoir pressure in chamber 17 will overcome the opposing pressures in the brake pipe chamber 12 and in the equalizing chamber the diaphragms will be moved upwardly and the pilot valve will be moved to lap position to prevent further escape of air from the chamoperation will be repeated.

' brake cylinder pressure maybe increased or diminished by steps by decreasing or increasing the brake pipe pressure.

f Automatic bra/ce cylinder pressure reflent/0a In4 operating trains equipped With the present standard freight brake, such as the Well known Vestinghouse K type ottriple valve, it isnthe usual practice to turn up pressure retainers when descending a grade. The purpose oitthe retainer is to hold a ccrtaiirpressure in the brake cylinder while ref leasing the brakes and i'e-chareimi the aux- D b O i iliary reservoir. lVhen descending grades witlihthe. trains equipped with the ordinary standard freight brake of the Westinghouse type it is the practice to apply the brakes to retard the speedof the train; to hold; the brakes applied for a brief period, about thirty oi forty seconds; to then release the brakes and re-charge theauxiliary reservoir, this release and recharging period being short, us-

ually forty to sixty seconds; and then it the grade is long and heavy to again apply the brakes for a brie2 period and to again release them and re-charge the auxiliary reservoir. T his operation isvdiat is known as cycling and-it is continued during the entire run down the grade. It the grade is heavy the application and holding and the release and i'e-charging operations follow each other rapidly and are of short duration. l't is esv sential that the release and re-charge operations shall be as short as possible and be tollowed immediately by a rep-application of the brakes in orderktol prevent undue acceleration Vof `the train on the grade. y

The retainers are Weighted or loaded valves which retain a certain portion ot the brake cylinder pressure during the period of release and re-charge. These retainers have What is called certain value, that is to say, they aie constructed to retain a certain,

number of vpounds pressure in the brake cylinder, and that fixes the value ot the retainers. These values vary for dillieieiit grades. Aretainer of light value will ybe usedon trains running down lovv grades and Ka retainer ofy high value will be used on trains running down heavy grades. The heavy value retainers retain a heavier pressure in the brake cylinders during the re- ,V lease and re-charging period.

The triple valve herein described provides means for automatically building up the. brake cylinder pressure during cycling oper ations and avoids the use of the manually settable retainers.

The release governing valve in graduated release position, as shown in Fig. 4*, pre-Y vents the exhaust of pressure from thev retention chamber 25 through the atmosplieric port 29. When the main slide valveq, is in release position the release cavity v2Ql thereof connects the brake cylinder passage. l9.to the portl 27 a leading into the retention chamber so that brake cylinder pressure `will flow into the retention chamber. A cavity 5o., 25c of the main slide valve will connect the, i port and passage 25b which leads fromL theretention cliambentoan atmospheric; port 25d. The chamber 25, as hereinbefore de scribed isconnectedto the retention chamber 5;,` 26 by passage 25a. Whenv the mainslide., valve is in release position the independent or pilot valve 15 will also be in release posif tion and brake cylinder pressure Willi be flowing through said valve to the atmosf, pheiic port 42. The ports 27a and 25b Will. be restricted ports, 251" being more restricted than 27a so that a certain predetermined proportion of the pressure flowing Vinto chamber 25 through the port 271 Willbe re- 95 tained therein and said pressure will be builtl up vin the retention chamber 26.' The, amount of pressurei built up inthe chamber 26 will be dependent upon the lengtlyojtl time the mainslide valveremainsin release ieu position. During the.` entire time that the main slide valve remains inrelease position brake. cylinder pressure will be lowirior into chamber 25` throughrport 27El and: will be flowing from said chamberlto atmosphere: 105. through the port 25". This flow ofairiwill not be interrupted when the independent: valve 15 is moved Ito, larp position. The pressure built up intlie retention chamber 264 will oppose, the brake cylinder pressure on v 110,.

the oaposite side ofthe.fdiapliiagin,53 butk Willa ways be lessthan said pressure. When the brake pipepressure is `again reduced fori another application of the brakes the .main

slide valve Will move to service position-A thereby cutting ott urtherdischarge of-5air from chamber 25 Aand interrupting the flow of air into .saidchamber.r Thus lthe pres,- sure built up `in chambers 25 vand 26Willf be retained thereinpand airwill flovvfrom 120,` the auxiliaryreservoir tothe brake cylinder as hereinbefore described. The reduction `of brake pipe pressurein chamberlQ will reV`V sult in the independent or.pilot'valvezmoving1 to service positionto` connect thebrake pipe to the brake cylinder. The independent valvet Will remain in. service positionv until@ the brake eylinderpressure builttup in chamber.l

55 will bev sufficient, with thefbrake pipe., pressure in A chamber 12, to overcome the i pressure in the retention chamber 26 and the emergency reservoir pressure in chamber 17. Because of the pressure retained in chamber 26 the pressure built up in the equalizing chamber 55 must be greater than would have been necessary with no pressure in the retention chamber. The result will be that a higher brake cylinder pressure will be built up and this degree of pressure will be dependent upon the amount of pressure trapped in the retention chamber. As hereinbetore stated the amount of pressure trapped in the retention chamber will be dependent upon the length et time the main slide valve remains in release position, the shorter the period of release the higher will be the pressure in chamber 26 and the longer the period of release the lower the trapped pressure will be. lt is therefore clear that i in cycling operations the brake cylinder pressure will be built up in accordance with the rapidity of the braking cycles. Gn heavy gradesthe cycling will be rapid and the periods of release will be short while on low grades cycling operations will be slower and the periods ci release will be longer. The result will be that when cycling on heavy grades there will be a greater build up 01"' brake cylinder pressure than there will be when cycling on low grades. lt is also manifest that by holding the main slide valve in release position for a suliicient time the entire brake cylinder pressure will be released. In these release operations the main slide valve is idle eXcept that it connects the small blow down or leak port 251 to atmosphere. rThe amount of brake cylinder pressure escaping through said port b will be small as compared with the amount of brake cylinder pressure exhausted through the independent pilot valve and the atmospheric port 42.

TWhen the release governing valve is in quick release position chamber 25 is open to atmosphere through the atmospheric port 29 and there will be no appreciable build up or accumulation of pressure in chambers 25 and 26 when the main slide valve is moved to release position.

Emergency position.

rlhe brake pipe pressure is reduced in the usual manner at an emergency rate for an emergency application of the brakes. This emergency reduction in chamber 1 will be sutiicient to permit the auxiliary reservoir pressure in chamber 5 to move the main ber 30" will be vented to atmosphere through passage 32, cavity 41 of the main slide valve and atmospheric port 42. Auxiliary reservoir pressure in chamber 9 will thereupon force the piston 30 inwardly to the position shown in Fig. 3 and the lever 30 will unseat the check valve 10 and permit the emergency reservoir air to flow direct to the chamber 5 through chamber 9 and passage 8. Air trom the auxiliary reservoir and the emergency reservoir will flow direct to the brake cylinder through the emergency port 63 of the main slide valve and brake cylinder passage 1.9.

The brake pipe vent valve is opened to etect a rapid and positive serial emergency action throughout the train. TWhen the main slide valve is in emergency position the chamber 36a above the vent valve piston 33 is vented into the chamber 39 through passage 3S, cavity 65 in the main slide valve, port and passage l0 which leads to the chamber 23S). Chamber 39 is at atmospheric pressure in all positions of the main slide valve except emergency position. When the chamber 36a is vented, as described, the brake pipe pressure below the piston 33 will raise said piston and open the brake pipe vent valveB-, thereby permitting brake pipe pressure to flow directly to atmosphere. Then the brake pipe pressure has been reduced sufficiently to bring about approximately an equalization between the pressure above and below the piston 38 the valve 3st will be closed by the spring 66 and the air velocity past the valve. The emergency operation of the triple valve, whether' operated in graduated release or in quick release, is precisely as described, en cept that when operating in graduated reease any pressure existing in the retention chamber at the time of the emergency operation will be held or trapped therein. Pressure in all ot the other chambers ot the triple valve will be equalized. As shown in F ig. 3 air will ilow from chamber 5 into chamber 12 through passage 11 when the main piston ltis in emergency position so that the pressures in chambers 12, and 17 will be equalized. Air will leak hrcugh the port 37 to more quickly bring about an equalization ot pressures on opposite sides ot the piston 33.

Release 0" HL@ bra/ses atte. rm emewcncz l j J applicano@ The release ot the brakes after an emergency application is obtained by increasing the brake pipe pressure above the brake cylinder pressure existing in chamber 5 at the right side of piston It-l. The parts will then assume release position and the system will again be charged as described. Should the release governing vvalve be in graduated relit) CAD

cation when a predetermined brake cylinder pressure is secured from auxiliary reservoir and brake pipe/` said secondary valve device being controlled by brake pipe7 brake cylinder and en'icrgency reservoir pressures.

6. triple Valve tor air brake ap] aratus comprising` a main slide valve a graduating valve, a piston connected to said valves and subject on one side to bralfe pipe pressure and on its other sioe to auxiliary reservoir pressure and operating` upon an increase or" brake pipe pressure to move said valves to release vposition to connect the bralre cylinder to a main exhaust-port and to open communication from the brake pipe to aux-- iliary reservoir. and operating upon a re duction of brake pipe pressure to move said valves to application position to connect the auxiliary reservoir to the brake cylinder and to close communication from the brake pipe to auxiliary reservoir, said communication with the brale cylinder being closed upon an equalization ot pressures in the brake pipe and in the auxiliary reservoir whereby a certain volume of air will be discharged from the auxiliary reservoir to the brake cylinder tor a given brake pipe reduction, a secondary or pilot valve subject to brake pipe7 brake cylinder and emergency reservoir pressures and operating upon reduction in bralre pipe pressure to connect the bralre .pipe to the brake cylinder and operating' upon an increase in brake pipe pressure to connect the bralre cylinder to atmosphere through a secondary exhaust port, a release governing valve having a quick release position andra araduated'release positioin said valve in quick release position opening the mein brake cylinder exhaust port to atmosphere and in its graduated release position closing;r said main exhaust port and openinn' communication between the brake cylinand the secondary exhaust port through the pilot valve whereby the pilot valve will control the exhaust of brake cylinder pressure when the release governing valve is in graduated release posit-ion,y Y and means w ereby the mainy slide valve will control brake cylinder exhaust through the pilot Vvalve and the secondary exhaust port,

'7. in air brake apparatus comprising an `encv reservoir, an auxiliary reservoir, a brake pipe, brake cylinder, main valve means subject to brake pipe pressure and auxiliary reservoir pressure and operating unen a reduction in brake pipe pressure to communication between the auxiliary lvoir and the brake cylinder and to close ation between the brake pipe and ,l 7 ,said communication with e cylinder being'rclosed upon ian ation ofrp essures in the brake'` pipe theaiixiliary reservoir whereby -a volume 'otr air `:will be discharged iroin" the gauxiliary*l #reservoir l 5to 'the' kbrake cylinder for a given brake pipe reduction, and a secondary or pilot valve operating upon a reduction of brake pipe pressure to at mit brake pipe air only to the brake cylinder until a predetermined pressure is built up in said brake cylinder from the auxiliary re,d 1voir and brake pipe, whereby the movement oi the said main valve means will be .ni ade certain by the local reduction of brake pipe pressure and the predetermined pressure in the brake cylinder will be maintained regardless of brake cylinder leaks and variations in brake cylinder piston travel.

8. An air brake apparatus comprising an emergency reservoir, an auxiliary reservoir, a brake pipe, a brake cylinder, main valve means subject to brake pipe pressure and axiliary reservoir pressure and operating upon a reduction in brake pipe pressure to open communication between the auxiliary reservoir and the brake cylinder and to close communication between the brake pipe and auxiliary reservoir, said communication with the. brake cylinder being closed upon an equalization of pressure in the brake pipe and inthe auxiliary reservoir whereby a certain volume of air will be discharged from the auxiliary reservoir to the brake Vcylinder for a given brake pipe reduction,

said main valve means operating upon an increase of brake pipe pressure to connect he brake cylinder to a'main exhaust port, means operating upon an increase of brake pipe pressure to slowly release brake cylinder pressure through a secondary exhaust port and independent of the main exhaust port of the main valve means and at a uuiform rate without regard to the degree of increased brake pipe pressure, and manually operable means in one position rendering the main exhaust means ineffective and the secondary exhaust means eiiective and in another position rendering the main exhaust means effective. and the secondary exhaust no means inetective.

9. Ain air brake apparatus comprising an emergency reservoir. an auxiliary reservoir, a brake pipe, a brake cylinder, main valve :means subject to brale pipe pressure and auxiliary reservoir pressure and operating upon a reduction in brake pipe pressure to open communication between the auxiliary reservoir' and the brake cylinder and to close communication between the brake pipe` and auxiliary reservoir, said communication with the brake cylinder being closed upon an equalization of pressure in the brake pipe and in the auxiliary reservoir ywhereby* a vcertain yolumefof airiwill be discharged 4irgnri,:the fauxiliaryeservoir ito the brake crllnderf or au, en l:brake pipe reduction', said main valve meansgioperating upon-an increase otr-*brake pipe pressure to connect .the brake cylinder to? a main exhaust .porte a secondary valve v means .operating=;upo1c;a

`reduction of brake pipe pressure to place "the brake pipe in communication with the jaryr exhaust port and independent of the main exhaust port of the main valve means, said secondary valve means being controlled f by brake pipe, b'ralre cylinder and emergency reservoir pressures, and manually operable nieans in one position rendering the main exhaust means ineffective and the tsecondary exhaust means eil'ective and in another position rendering fthe main exhaust means Aeffective and they secondary exhaust means ineffective.

10. An yair brake apparatus comprising an 'emergency reservoir, an yauxiliary reservoir, 'a brake pipe, a brake cylinder, main valve means subject to brake pipe pressure and auxiliary reservoir pressure and operating upon a reduction in brake pipe pressure to open communication between the auxiliary reservoir and the brake cylinder and to close lcommunication ybetween the brake pipe and auxiliary reservoir, said communication with the brake 'cylinder being closed upon an :equalization of pressure in the brake pipe and in the auxiliary reservoir whereby a certain volume of air will be discharged Vfrom the auxiliary reservoir to the brake cylinder for a given brake pipe reduction, said main valve means operating upon an increase of vbrake pipe pressure to connect the brake cylinder to 'a main exhaust port, a *secondary indep ndent valve operating upon a reduction in brake pipe pressure to connect thel brake pipe to Vthe brake 'cylinder -a'nd to close said communication when a predetermined bralre cylinder pressure is secured `trom the auxiliary reservoir and the brake pipe and operating upon 'an increase "of brake pipe pressure to release position to `connect the brake cylinder to atmosphere through a secondary 'exhaust port, means controlled by brake pipe and 'brake cylinder `pressures opposed to the pressure of an enierg- Jv'ency reservoir for actuating said independent valve, yand means whereby said pressure controlling valve will maintain the brake cylinder pressure in direct proportion to the .'brake .pipe reduction the brake cylinder pressure moving said independent valve to release position when said pressure exceeds the desired brake cylinder pressure, and emergency reservoir pressureV moving said valve to application position when the brake cylinder pressure is below the desired brake cylinder pressure.

11. A triple valve for air brake apparatus comprising a main slide valve, a graduating valve, a piston connected to said valves and subject on one side to brake pipe pressure and on its other side to auxiliary reservoir pressure and operating upon an increase of brake pipe pressure to move the said valves to release position to connect the brake cylinder to a main exhaust port and to open `communication from the brake pipe to auxiliary reservoir, and operating upon a reluction ol brake pipe pressure to move said valves to application position to connect the auxiliary reservoir to the brake cylinder and to close communication from the brake pipe to auxiliary reservoir, said communication with the brake cylinder being closed upon an equalization of pressures in the brake pipe and in the auxiliary reservoir whereby a certain volume of air will be discharged 'from the auxiliary reservoir to the brake cylinder for a given brake pipe reduction, a secondary independent valve control-ling a restricted secondary exhaust port adapted to slowly release brake cylinder pressure upon an increase in brake pipe pressure tor a lease of the brakes, and means controlled by brake pipe Iand brake cylinder pressures opposed to the pressure of an emergency reservoir for actuating said independent valve.

`12. A triple valve for air brake lapparatus comprising a main slide valve, a graduating valve, a piston connected to said valves 'and subject on one side to brake pipeV pres and on its other side to auxiliary ref-:crvoir pressure and operating upon an increase et brake pipe pressure to move the said valves to release position to connect the brake cylum w inder to a main exhaust port and to vopen valves to application position to connect theV auxiliary reservoir to the bralre cylinder and to close communication from the brake pipe to auxiliary reservoir, said communication with the brake cylinder being closed upon an equalization of pressures in the brake pipe and in the auxiliary reservoir whereby a certain volume of air will be dischi?b d from the auxiliary reservoir to Vthe brake cylinder for a given brake pipe reduction, and a secondary independent valve operating upon a decrease in brake vpipe pressure to connect the brake pipe alone to the brake cylinder through a cavity in the main valve when said slide valve is in service application position. Y

13. A triple valve for air brake apparatus comprisingl a main slide valve, a graduating; valve, a piston connected to said valves and` subject on one side to'bralre pipe pressure Yll() the? iary reservoir, and operating upon a reduction of brake pipe pressure to more said Valves to application position to connect the auxiliary reservoir to the brake cylinder and to close communication from the hralre pipe to auxiliary reservoir, said communi with the brake cylinder being closed an equalize-tion or pressures in hi pipe andin the auxiliary reservoir Where a certain Volume oic air will be dis-cna from the auxiliary reservoir to the cylinder for a given bra pipe reen ion a secondary independent valve ope upon decrease in brake pipe pre.L connect the brake pipe alone to the cylinder through a cavity in the irain Valve When said slide Valve is in service application position, and ineens controlled by brake pipe and brake cylinder preM opposed to the pressure of an ef- I reservoir for actuatingsaid independ Valve.

14. A triple valve for air hralre app comprising` a main slide valve, a grad Valve, a piston connected zo valves an -z subject on one side to hrlre pipe pre'gsure and on its other side to auxiliary resem-oir pressure and operating upon n increase brake .pipe pressure to more the said to release position to connect elle cylinder to a niain exhaust port and to oi communication from tlie brake pipe to au iary reservoir, and operating upon a tion of brake pipe pressure to valves to application position to connect auxiliary reservoir to the loralre cylii to close communication from the lei-alie p to auxiliary7 reservoir, said coniniunicat. with the brake cylinder being clos upc an equalization of pressures in tiie orali-f pipe and in the auxiliary reservoir Whe-rch; a certain `rolun'ie of air will he discharejef from the auxiliary reservoir to the h cylinder for a giyen hralre pipe red a quier release Valve contro a iiiain i haust through the main valve adapted to be inanuallj.7 operated to rein the main exhaust ineffective in rclease'opcrations, and a secondary independent perating' upon. a decrease 'l' aressure to connect the lira1 e pipo to brake cylinder and operatinCE upon an increase in brake pipe pressure to release position to connect the bralre cylinder to almosphere through a secondary restricted port.

l5. A triplel Valve for air brake apparatus comprising a niain slide valve, a graduating valve, a piston connected to said valves and subject on onezside to hralregpipe ipressure a anfdfionafits: othergside :to: iaiixiliary ireseryoir:pressure and operating uponan fincrease'zo'f brake pipe pressureftey more: `the toxconnect ,i

,il ralre f cylinder to; 'las rnain j iexhanst? port p andfto operi communication; troni-gtlie; brake 1 ali/es to release 1 ip esiti contro i. hraxe pipe pipe to auxiliary reservoir, and operating' upon a reduction oi brake pipe pressure to more said valres to application position to connect the auxiliary reservoir to the brake effin-der and to close communication `from the brake pipe to auxiliary reservoir, said communication with the hralre cylinder beclosed upon an equalization of pressures in the hralrc pipe and in the auxiliary reservoir whereby a certain volume or air will ,-e discharged from the auxiliary reservoir o the lnalre cylinder for a given brake ipe reduction, a .Quick release Valve conrolling;N a main exhaust through the main li'le vali-re and adapted to he manually perated to r nder the main exhaust through the slide valve inei'lective in release operations, a secondary independent Valve operating upon a decrease in brake pipe pressure to connect the hralre pipe to the hralre cylinder and operating` upon an increase in brake pipe pressure to release position to connect the hralre cylinder to atmosphere through a secondary port, and means led by hralre pipe and brake cylinder es opposed to the pressure or an I reservoir for actuating` said independent valve. l

16. i triple valve for air brake apparatus comprising a main slide Valve, a graduating' valve, a piston connected to said valves and on one side to hralre pipe pressige and on its other side to auxiliary reseryoir pressure and operating upon an rease of loralre pipe pressure to more said Valves to release position to Ycznnzcct they hralre cylinder to a inain ei:-

' pressure to more said Valves to application positionH to connect the auxiliary reservoir to the hralre cylinder and to close communication 'from the brake pipe to auxiliary reservoir, said communication with thc brake cylinder heine` closed pon an equalization or pressures in the hralre pipe and in the auxiliary reseryoir uf'hcrchy a certain. Volume oi air will he discharged 'from the lieny reservoir to the brake cylinder for a gir-en hralre pipe reduction, a quicl -elease Valve controlling` a main exhaust through the main slide valve and acapted to be manually operated to render the inain exhaust nirough tlie'inain slide 1valve ineffectiye release operations, secondary independent ralre operating-upon a decrease in liralre pipe to connect the hralre ito thehralre Acylindenand 'operating crease i-. -Lhrake,.pipe?pressure:to

release positionto connect the brake cylin- 4oY atmosphere throi, 'i t poi nieaiiscontr ralre cylinder pr i secondary exlfd hy; lira-he :pipe

i-gencyieseryoin for i actuating said independent valve, and means whereby said pressure controlling valve will maintain the brake cylinder' pressure in 'direct proportion to the brake pipe reduction.

17,. A triple valve for air brake apparatus comprising a main slide valve, a graduating valve, a piston connected to said valves and subject on one side to brake pipe pressure and on its other side to auxiliary reservoir pressure and operating upon an increase oi brake pipe pressure to move the said valves to release position to connect the brake cylinder to a main exhaust port and to open communication from the brake pipe to auxiliary reservoir, and operatingupon a reduction of brake pipe pressure to move said valves to application position to connect the auxiliary reservoir to the brake cylinder and to close communication from the brake pipe to auxiliary reservoir, said communication with the brake cylinder being closed upon an equalization of pressures in the brake pipe and in the auxiliary reservoir whereby a certain volume of air will be vdischarged from the auxiliary reservoir to the brake cylinder for a given brake pipe reduction, a quick release valve controlling a main exhaust through the main slide valve and adapted to be manually operated to render the main exhaust through the main slide valve ineffective in release operations, a secondary independent valve operatingrupon a decrease in brake pipe pressure to connect the brake pipe to the brake cylinder and operating upon an increase in brake pipe pressure to release position to connect the brake cylinder to atmosphere through a secondary exhaust port, means controlled by brake pipe and brake cylinder pressures opposed tothe pressure oit emergency reservoir tor actuating said independent valve, and means whereby said pressure controlling valve will maintain the brake cylinder pressure in direct proportion to the brake pipe reduction the brake cylinder pressure moving said independent valve to release position when said ,pressure exceeds the desired brake cylinder pressure, and emergency reservoir pressure moving said valve to application position when the brake cylinder pressure is below the desired brake cylinder pressure.

18. A triple valve for air brake apparatus comprising a main slide valve, a graduating valve, a piston connected to said valves and subject on one side to bralre pipe pressure and on its other side to auxiliary reservoir pressure and operating upon an increase of bra-ke pipe pressure to move the said valves to release position to connect the brake cylinder to a main exhaust port and to open communication 'from the bralre pipe to auxiliary reservoir and operating upon a reduction of brake pipe pressure to move said valves to application positionto connect the auxiliary reservoir to the brake cylinder and to close communication from the brake pipe to auxiliary reservoir, said communication with the brake cylinder' being closed upon an equalization of pressures in the brake pipe and in the auxiliary reservoir whereby a certain volume of air will be discharged from the auxili,aryreservoir to the brake cylinder for a given brake pipe reduction, a secondary independent brake cylinder pressure controlling valve adapted in service position to connect the bralre pipe to the brake cylinder through a cavity in the main slide valve when said slide valve is in service application position, and means controlled by brake pipe and brake cylinderV pressures opposed to the pressure of an emergency reservoir for actuating said independent pressure controlling valve.

19. A triple valve for air brake apparatus comprising a. main slide valve, agraduating valve, a piston connected to said valves and subject on one side to bralre pipe pressure and on its other side to auxiliary reservoir pressure and operating upon an increase ot bralre pipe pressure to move the said valves to release position to connect the brake cylinder to a main exhaust port and to open communication from the brake pipe to auxiliary reservoir, and operating upon a reduction ot brake pipe pressure to move said valves to application position to connect the auxiliary reservoir to the bralre cylinder and to close communication from. the brake pipe to auxiliary reservoir, said communication with the brake cylinder being` ,closed upon an equalization of pressures in the brake pipe. and in the auxiliar;7 reservoir whereby a certa-in volume of air will be discharged from the auxiliary reservoir to the brake cylinder for a given brakeV pipe reduction, a secondary independent valve operating upon a decrease in brake pipe pressure to connect the brake pipe to the brake cylinder and operating upon au increase in brake pipe pressure to release position to connect the brake cylinder to atmosphere through a secondary port, means controlled by brake pipe and brake cylinder pressures opposed to the pressure of an emergency reservoir for actuating said independent valve, and means whereby said pressure controlling valve will maintain the brake cylinder pressure in direct proportion to the brake pipe reduction.

20. A triple valve for air brake apparatus comprising a main slide valve, and a pistou connected to said valve and subject on one side to brake pipe pressure and on its other side Y to auxiliary reservoir pressure and operating upon an increase of brake pipe pressure to move the main valve to release position and operating upon a reduction oi brake pipe pressure to move said valve to build up the brake cylinder pressure.

2l. i triple valve Ji'or air brake apparatus comprisingl a main slide valve, and a piston connected to said valve and subject on one zside to brake pipe pressure and on its other lside to auxiliary reservoir pressure and operating upon an increase of brake pipe pressure to move the main valve to release position and operating` upon a reduction oi brake pipe pressure to move said valve to application position to connect the auxiliary reservoir to the brake cylinder, in combination With a pilot valve subject to brake pipe, brake cylinder and emergency reservoir pressures,fthe brake cylinder' pressure moving said pilot valve to lap position, and means whereby the brake cylinder pressure will be built up by cycling operations.

22. A triple valve for air brake apparatus comprising a main slide valve, and a piston connected to said valve and subject on one side to brake pipe pressure and on its other :side to auxiliary reservoir pressure and .operating upon an increase Oibrake pipe pressure to move the main valve to release position and operating' upon a reduction ot brake pipe pressure to move said valve to ,application position to connect the auxiliary reservoir to the brake cylinder, and provided With automatically operating` means `to build up brake cylinder pressure by cycling operations, the extent of the buildup of brake cylinderI pressure depending .upon the rapidity of the cycling operations.

23. A triple valve for air brake apparatus comprising' aina-in slide valve, a piston connected to said valve and subject on one side to brake pipe pressure. and on its other side to auxiliary reservoir pressure and operating upon an increase ot brake pipe pressure to move the main valve to release position and operating` upon a reduction of brake pipe .pressure to move said valve to application position to connect the auxiliary reservoir to the brake cylinder, and providedV with a pilot valve and means whereby the main slide valve Will build up brake cylinder pressure by cyclingl operations, the extent of the build-up of brake cylinder pressure depending upon the. rapidity 0l' the cycling operations, and a release governing valve having a graduated release position and a quick release position, said valve in its quick release position preventing the build up of brake cylinder pressure and in its lgraduated release position permitting the said build up oit brake cylinder pressure.

24. A triple valve for air brake apparatu con'iprising a main slide valve, a piston connected to said valve and subject on one side to brake pipe pressure and on its othery side to auxiliary reservoir pressure and operating upon an increase of brake pipe pressure to move the Amain valve to release position and operatingupon a reduction of brake pipe pressure to move said valve to application position to connect the auxiliary reservoir to the brake. cylinder, and provided With automaoically operating means to build up brake rcylinder pressure by cycling operations, the extent of the build-up of brake cylinder pressure depending` upon the rapidity of the cycling operations, and a release governing valve. having` a graduated release position and a quick release position, said Valve in its quick release, position preventing,- the build-up ot brake cylinder pressure and in its graduated release position permitting the said build-up of brake cylinder pressure.

25. A triple valve or air brake apparatus comprising` a main slide valve, a piston connected to said valve and subject on one side to brake pipe pressure and on its other side to auxiliary reservoir pressure and operating upon an increase oit brake pipe pressure to move the main valve to release position and operating upon a reduction of brake pipe pressure to move said valve to application position to connect the auxiliary reservoir to the brake cylinder, and provided with a brake cylinder pressure control chamber, a pilot valve, a retention chamber,means operating upon a. reduction of brake pipe pres-f sure to move the pilot valve to application position to admit air into the brake cylinder pressure control chamberV and to the brake cylinder, said means operating upon an increase in brakel pipe pressureto move the pilot valve to release position to connect the control chamber to atmosphere, and means to move said pilot valve to lap position to close communication between the control chamber and the brake cylinder, the main slide valve in release position connecting` the brake cylinder to the retention chamber and the retention chamber to atmosphere through a restricted port.

26. A triple` valve for air brake apparatus comprising a main slide valve, a piston connected to said valve and subject on one side to brake pipe. pressure and on its other side to auxiliary reservoir pressure and operating upon an increase of brake pipe pressure to move the main valve to release position and operating,` upon a reduction of brake pipe pressure to move said valve to applicationV position to connect the auxiliary reservoir to the brake cylinder, a r tention chamber, the main slide valve in release posit-ion connecting the brake cylinder to the retention chamber and to atmosphere, the said main valve in service position closing,` vcommunication between the brake cylinder and the retention chamber and the retention chamber and atmosphere.

27. A triple valve for air brake apparatus voperations, the extent of the build-up ot' brake cylinder pressure depending upon the rapidity ot' the cycling operations.

278. A triple valve for air brake apparatus comprising a main slide valve, a piston connected to said valve and subject on one side to brake pipe pressure and on its other side to auxiliary reservoir pressure and operating upon an increase ot' brake pipe pressure to move the mainy valve to release position and'operating upon a reduction oi' brake pipe pressure to movel said valve to application position to connect the auxiliary reservoir to the brake cylinder, and means whereby the main slide valve will automatically build up brake cylinder pressure by cycling operations.

29. An air brake apparatus comprising an emergency reservoir, an auxiliary reservoir, a brake cylinder, a brake pipe, a main valve device and a secondary valve device both of said devices being operated bya reduction of brake pipe pressure, the main valve device closing communication between brake pipe and auxiliary reservoir and placing the auxiliary reservoirin communication with the brake cylinder and closing said brake cylinder communication upon an equalization of brake pipe and auxiliary reservoir pressures, whereby a certainyolume of air will be dis- Charged from the auxiliary reservoir into the brake cylinder for a given brake pipe reduction, said main valve device also operating upon a sudden reduction of brake pipe pressure to place the emergency reservoir and auxiliary reservoir in communication with the brake cylinder for an emergency application ot the brakes, the secondary valve device placing the brake pipe vin c0mmunication with the brake cylinder and closing lsaid communication when a predetermined brake cylinder pressure is secured .from auxiliary reservoir and brake pipe,

said secondary valve device being controlled by brake pipe, brake cylinder and emergency reservoir pressures, and means whereby the main slide valve in service position will connect the brake cylinder to the brake pipe through the secondary valve and will connectv the brake cylinder to atmosphere through passages controlled by the secondary valve.

30. An air brake apparatus comprising an emergency reservoir, an auxiliary reservoir, a brake cylinder, a brake pipe, a main valve device and a secondary valve device both of said devices being operated by a reduction oi braire pipe pressure, the main valve de vice closing communication between brake pipe and auxiliary reservoir and placing the auxiliary reservoir in communication with the bral-:e cylinder and closing said brake cylinder communication uponY an equalization of brake pipe and auxiliary reservoir pressures, whereby a certain volume of air will be discharged from the auxiliary reservoir into the brake cylinder for a given brake pipe reduction, said main valve device also operating upon a sudden reduction of brake pipe pressure to place the emergency reservoir and auxiliary reservoir in communication with. the brake cylinder for an emergency application of the brakes, the secondary valve device placing the brake pipe in communication with the brake cylinder and closing said communication when a predetermined brake cylinder pressure is secured from auxiliary reservoir and brake pipe, sait. secondary valve device being controlled by brake pipe, brake cylinder and emergency reservoir pressures, means whereby the main slide valve in service position will connect the brake cylinder to the brake pipe and will connect the brake cylinder to atmosphere through passages controlled by the independent valve, and means whereby the main slide valve in emergency position will close the passages controlled by the independent valve.

3l. An air brake apparatus comprising an emergency reservoir, an auxiliary reservoir, a brake cylinder, a brake pipe, a main valve device and a secondary valve device, both of said devices being operatedvby a reduction of brake pipe pressure, the main valve de.- vice closing communication between brake pipe and auxiliary reservoir and placing the auxiliary reservoir in communication with the brake cylinder and closing saidk brake cylinder communication upon an equalization of brake pipe and auxiliary reservoir pressures, whereby a certain volume of air will be discharged from the auxiliary reservoir into the brake cylinder for a given brake pipe reduction, the secondary valve device placing the brake pipe in communication with the brake4 cylinder Vand closing said communication when a predetermined brake cylinder pressure is secured from auxiliary reservoir and brake pipe, said secondary valve device being controlled by brake pipe, brake cylinder and emergency reservoir pressures, and means whereby the Vmain slide valve in emergency position will render the secondary valve device ineffective.

82. A triple valve tor air brake apparatus comprising a main slide valve, a graduating valve, a piston connected to said valves and subject on one side to brake pipe pressure l brake and'on its other side to auxiliary reservoir pressure and operating upon an increase ot brake pipe pressure to move the said valves to release position to connect the brake cylinder to a main exhaust port and to open cor munication from the brake pipe to auinnary reservoir, and operating upon a reduction ol bralie pipe pressure to move salie valves to application position to connect the auxiliary reservoir to the bralre cylinder and kto close communication from the bralre pipe to auxiliary reservoir, said communication with the brake cylinder being closed upon an equalization of pressures in the bralre pipe and in the auxiliary reservoir whereby a certain volume of air will be discharged from the auxiliary reservoir to the brake cylinder for a given brale pipe reduction, secondary or pilot alve subject to brale pipe, brake cylinder' and emerge" cy reservoir pressures and operating upon a reduction in brake pipe pressure to connect the bralre pipe to the bralre cylinder and operating upon an increase in bra-ke pipe pressure to connect the brake cylinder to atmosphere through a secondary exhaust port, and means whereby the main slide valve in emergency position will render the secondary valve device ineffective.

33. An air brake apparatus comprising an emergency reservoir, an auxiliary reservoir, a brake pipe, a brake cylinder, main valve means subject to brake pipe pressure and auxiliary reservoir pressure and operating upon a reduction in 1oralre pipe pressure to open communication between the auxiliary reservoir and the cylinder and to close communication between the brake pipe and auxiliary reservoir, said communication with the bralre cylinder being closed upon an equalization of pressures in the bralre pipe and in the auxiliary reservoir whereby a certain volume of air will be discharged Jrom the auxiliary reservoir to the brake cylinder for a given brake pipe reduction, a secondary or pilot valve operating upon a reduction ot brake pipe pressure to admit bralre pipe air only to the brale cylinder until a predetemined pressure is built up in said brake cylinder from the a :riiiary reservoir and brake pip-e, whereby the movement ofthe said main valve means will be made certain by the local reduction ont brake pipe pressure and the predetermined 'pressure in the brale cylinder will be maintained regardless of bralre cylinder leals and variations in brake cylinder piston travel, means whereby the auxiliary reservoir pressure will hold the emergency reservoir sealed in the service position or' the main valve means, and means whereby the main valve in emergency position will permit auxiliary reservoir pressure to open communication between emergency reservoir and the auxiliary reservoir for emergency application ot the bralres.

ltriple valve for brake apparatus comprising a main slide valve, a gra-:iluating valve, a piston connected to said valves and subject on one sid to brake pipe pressure and on other side to auxiliary reservoir pres are and ope -ting upon an increase oi brake pipe pres to move the said valves to release position to connect the brake cylinder to a main exhaust port andto open corrv unic J'ion from the brake pipe to auxd i ci voir, and operating upon a reduc-- tion of bralre pipe pres e to move said valves to application posi Aon to connect the auxiliary r ,ervoir to the brake cylinder andV to close communication from the brake pipe to auxiliary reservoir, said communication with the bralre cylinder being closed upon an equalization of pressures in the brale pipe c ud in the auxiliary reservoir whereby a certain volume oi air will be discharged from the auxiliary reservoir to the bralre cylinder for a given brake pipe reduction, and provider with a pilot valve and means .vhereby the main slide valve will build up bralre cylinder pressure by cycling operations, the extent of the build-up of brake cylinder pressure depending upon the rapidity o1 the cycling operations, and a relcasegoverning valve having a graduated release position and a quick release position, said valve in its quick release position preventing the build up of brake cylinder pressure and in its graduated release position permitting the said build up of bralre cylinder pressure.

35. An air brake apparatus comprising an emergency reservoir, an auxiliary reservoir, a brake cylinder, a brake pipe, a main valve device, a pilot valve device, means whereby the main valve device will operate upon a reduction of brake pipe pressure to connect the auxiliary reservoir to the brake cylinder and then close said communication upon a substantial equalization of brake pipe and auxiliary reservoir pressures, means whereby the pilot valve will move to application position and connect the brake pipe to the brake cylinder upon a reduction of brake pipe pressure, means whereby the pilot valve will maintain the bralre cylinder pressure at a predetermined ratio to the brake pipe reduction, said pilot valve moving to release position when the brake cylinder pressure ei:- ceeds the predetermined ratio to the brake pipe reduction and moving to application position when the brake cylinder pressure is below the predetermined ratio to the brake pipe reduction, and means whereby the main and pilot valves will be moved to release position upon an increase of brake pipe pressure.

36. An air brake apparatus comprising an emergency reservoir, an auxiliary reservoir, a brake pipe, a brake cylinder, main valve Tecn- A an equalization of pressure in the brake pipe and Vin the auxiliary reservoir vherehy a certain `volume oi air will he discharged from the auxiliary reservoir to the lnalieV cylinder for a given brake pipe reduction, said main valve means operating' upon an increase of brake pipe pressure to connect the hralre cylinder te a main exhaust port, a secondary valve means operating` upon a reduction of lara-lle pipe pressure to place the bra-kc pipe in ccmmunicatien with the hrale cylinder and close said communication when a predetermined brake cylinder pressure is secured from the auxiliary reservoir and brakepipe, and operating upon an increase of brake pipe pressure to slowly release brake cylinder pressure to a. secondary exhaust pert and independent of the main exhaust port oi' the main Valve means, said secondajyY valve ineans being controlled by hral-re i:L e, brake cylinder and emergency reservoir pressures, manually ineens in one position rendering the main exhaust means ineffective and the secondary exhaust means effective and in another position rendering` the main exhaust means effective and the secondary exhaust means nelective, and means whereby said secondary valve will in all positions et the said manually operable means establish and maintain the hra cylinder pressure in direct proportie-n to a given brake pipe pressure reduction and Will, when the main exhaust is ineffective, reduce and maint-ain brake cylinder pressure in direct prepertion to a given increase in brake pipe pressure.

In testimony whereof 1 hereunto affix my signature.

SPENCER G. NEAL.

operable 

